1. Field of the Invention
The present invention relates to a screen microscope and, more particularly, to a screen microscope arranged chiefly for the purpose of observing an image projected on a screen and enabling to observe also by an eyepiece.
2. Description of the Prior Art
For medical examination, for example, cytodiagnosis, examination of feces, examination of urine, examination of blood corpuscle, etc., it is necessary to examine for a long time by means of a microscope. Therefore, examiners who perform such examinations suffer from considerable asthenopia which often causes various lesions. As a method for solving such problem, it is known to observe by projecting the image obtained by the microscope into a screen.
As the devices for observing the image obtained by the microscope by projecting it onto a screen, screen attachments for microscope as shown in FIG. 1 are known. Most of such screen attachments for microscope are arranged to mount a projection screen 3, instead of a photographing device, onto a photo-tube 2 of the microscope 1 or arranged to dismount the microscope tube and to mount the projection screen instead of it.
In case of such known attachments, however, the position of the projection screen 3 becomes high. When, therefore, moving a stage or operating a focusing part by observing the image projected onto the screen 3a, it is rather difficult to perform such operations and these known attachments are not suited for observation for a long time. Moreover, when alternately repeating to observe the image of the object by an eyepiece 4 and to observe the image of the object projected onto the screen 3a by using the above-mentioned known attachments, the height of the observing point by the eyepiece is quite different from the height of the observing point by the screen and it is very inconvenient. Moreover, in case of the screen attachment for microscope as shown in FIG. 1 for which the projection screen is to be interchanged with the photographing device, it is necessary to interchange the screen attachment with the photographing device every time when it is desired to record the observed image and it is also very inconvenient.